It's a split advertisement, so it's a vertical split advertisement.

So AB=BD because ABCD is a diamond.

So AB=AD, so the triangle ABD is an equilateral triangle.

So ∠A=∠C=60

So ∠ d = ∠ ABC =180-60 =120.

Because Abe = CBF =180-90-60 = 30.

So ∠EBF= 120-30-30=60.

I hope to adopt O (∩ _ ∩) O. Thank you.